(CBS News) Growing weary of the battle for the GOP presidential nomination?

Tough luck.

Rick Santorum's relatively strong night on Super Tuesday- as of this story, he won three states and came within a percentage point of a win in the closely-watched contest in Ohio - means that Mitt Romney has missed a huge chance to start wrapping up the GOP presidential nomination and focusing on President Obama.

To be sure, Romney is still the frontrunner for the nomination: He will wake up on Wednesday with more delegates than any of his rivals, along with a significant financial and organizational advantage over the rest of the field. According to exit polls, Republicans overwhelmingly continue to see Romney as having the best chance to beat Mr. Obama in the fall - and more than four in ten Ohio voters chose electability as the most important factor in their vote Tuesday. While CBS News is still estimating Romney's delegate haul as well as that of his rivals, Romney's big wins in Massachusetts, Virginia and Idaho netted him a big chunk of delegates in the race for 1,144 needed to win the nomination.

But Romney's weak performance Tuesday renews questions about whether Republican voters will ever be able to warm to the former Massachusetts governor. Romney simply hasn't shown the ability to break through and connect with a diverse coalition of Republican voters. Exit polls show that Romney struggled to attract very conservative, born again and evangelical voters; Ohio Republicans under 45 years old favored Santorum over Romney by double digits. Meanwhile, just 35 percent of Ohio voters who backed Romney said they "strongly favor" him.

And all this comes despite Romney's camp significantly outspending their rivals on the airwaves. Romney and the super PAC backing him outspent Santorum and his super PAC by about a 4-1 margin in Ohio, according to a Wall Street Journal tally of ad spending. The Associated Press reported Sunday that Romney and the super PAC backing him have been responsible for more than half of the more than $75 million in GOP ad spending thus far.

The former Alaska governor, who says she will support Romney if he is the nominee, said Republicans are concerned that Romney is the frontrunner only because he has more money and better organization than his rivals - an advantage the GOP nominee will not have in the general election.

It all adds up to a situation in which the nasty GOP race appears likely to slog on into the summer and possibly all the way to a contested convention in August, to the chagrin of Republicans worried that a long primary process could doom their nominee in November.

If the race does indeed become a slog, Romney has to hope that Gingrich doesn't drop out. The former House speaker won only his home state of Georgia on Wednesday, but he cast the outcome as a triumph anyway and said he would stay in the race.

"I am the tortoise, I just take one step at a time," said Gingrich, who complained the "elites" and the media and Republican Party have long been too quick to write him off.

Santorum on the other hand, has to hope Gingrich drops out as soon as possible. If he doesn't -- and it depends significantly on whether billionaire casino magnate Sheldon Adelson keeps pouring millions into the super PAC backing Gingrich -- it would mean that the "anti-Romney" conservative vote continues to be split.

The Santorum campaign has so far stopped short of calling on Gingrich to leave the race for the good of the conservative movement, but it's certainly putting the pressure on.

"There's been poll after poll after poll that shows if Rick Santorum were just to have a one on one shot with Mitt Romney that the Gingrich supporters go right to Rick Santorum in big numbers," Santorum senior strategist John Brabender told reporters Tuesday. "So conservative and Tea Party folks are going to have a decision to make: Do we want Mitt Romney to be the nominee or not, or do we want to just keep splitting our vote."

Both Santorum and Gingrich are now focused on winning the two southern states holding primaries next Tuesday -- Alabama and Mississippi -- with a focus on building up delegates in the South through the Texas primary in May. If Gingrich drops out, Santorum could end up winning many of those contests and putting even more pressure on Romney.

Still, none of the GOP presidential candidates other than Romney -- among them Ron Paul, who has focused on building up delegates in caucuses but has yet to win a state -- seem to have a clear path to the nomination. Nonetheless, their continue presence will make it difficult for the former Massachusetts governor to reach the 1,144 threshold before the convention - if he gets there at all.

Had Romney won Tennessee - a state that isn't a natural fit for him - and taken Ohio handily, it would have made Romney appear inevitable, which could have helped skeptical voters in the GOP base get over their misgivings and get on board. That, in turn, could have led to a series of wins that would have forced the other candidates out of the race. Instead, there's a good chance that every state in the union will have a chance to feel politically relevant this cycle, with political watchers paying close attention to every contest straight through to the Utah primary in late June.

The Romney campaign certainly hoped to wrap up this nomination early, but it has the resources and organization to fight for every last delegate. Despite Tuesday's outcome, most political watchers still expect the former Massachusetts governor to be the last man standing in this turbulent campaign cycle. But Super Tuesday has not settled the GOP race, and Mitt Romney has not settled GOP voters' doubts. Which means the fight for the Republican presidential nomination likely just got a whole lot longer.